diff --git a/src/cli.rs b/src/cli.rs
index 4a6ca1ac..c86ce035 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -14,6 +14,7 @@ mod footprint_opts;
 mod nucleosome_opts;
 mod pileup_opts;
 mod predict_opts;
+mod qc_opts;
 mod strip_basemods_opts;
 
 // include the subcommand modules as top level functions and structs in the cli module
@@ -27,6 +28,7 @@ pub use footprint_opts::*;
 pub use nucleosome_opts::*;
 pub use pileup_opts::*;
 pub use predict_opts::*;
+pub use qc_opts::*;
 pub use strip_basemods_opts::*;
 
 //
diff --git a/src/cli/qc_opts.rs b/src/cli/qc_opts.rs
new file mode 100644
index 00000000..3bc71de2
--- /dev/null
+++ b/src/cli/qc_opts.rs
@@ -0,0 +1,9 @@
+use crate::utils::input_bam::InputBam;
+use clap::Args;
+use std::fmt::Debug;
+
+#[derive(Args, Debug)]
+pub struct QcOpts {
+    #[clap(flatten)]
+    pub input: InputBam,
+}
diff --git a/src/subcommands.rs b/src/subcommands.rs
index 75aed803..e8f4fd59 100644
--- a/src/subcommands.rs
+++ b/src/subcommands.rs
@@ -16,5 +16,7 @@ pub mod footprint;
 pub mod pileup;
 /// m6A prediction
 pub mod predict_m6a;
+/// Collect QC metrics
+pub mod qc;
 /// Remove base modifications from a bam record
 pub mod strip_basemods;
diff --git a/src/subcommands/qc.rs b/src/subcommands/qc.rs
new file mode 100644
index 00000000..7d79bedc
--- /dev/null
+++ b/src/subcommands/qc.rs
@@ -0,0 +1,108 @@
+use crate::cli::QcOpts;
+use crate::fiber;
+use anyhow::Result;
+use ordered_float::OrderedFloat;
+use std::collections::HashMap;
+
+pub struct QcStats {
+    pub fiber_count: i64,
+    // hashmap that stores lengths of fibers
+    pub fiber_lengths: HashMap<i64, i64>,
+    // length of msps
+    pub msp_lengths: HashMap<i64, i64>,
+    // lengths of nucleosomes
+    pub nuc_lengths: HashMap<i64, i64>,
+    // number of ccs passes per read
+    pub ccs_passes: HashMap<OrderedFloat<f32>, i64>,
+    /// m6as per read   
+    pub m6a_count: HashMap<i64, i64>,
+    // m6as over total AT count
+    pub m6a_ratio: HashMap<OrderedFloat<f32>, i64>,
+    // add rq to stats
+    pub rq: HashMap<OrderedFloat<f32>, i64>,
+}
+
+impl QcStats {
+    pub fn new() -> Self {
+        Self {
+            fiber_count: 0,
+            fiber_lengths: HashMap::new(),
+            msp_lengths: HashMap::new(),
+            nuc_lengths: HashMap::new(),
+            ccs_passes: HashMap::new(),
+            m6a_count: HashMap::new(),
+            m6a_ratio: HashMap::new(),
+            rq: HashMap::new(),
+        }
+    }
+
+    pub fn add_read_to_stats(&mut self, fiber: &fiber::FiberseqData) {
+        self.full_read_stats(fiber);
+        self.add_m6a_stats(fiber);
+        Self::add_range_lengths(&mut self.msp_lengths, &fiber.msp);
+        Self::add_range_lengths(&mut self.nuc_lengths, &fiber.nuc);
+    }
+
+    fn full_read_stats(&mut self, fiber: &fiber::FiberseqData) {
+        self.fiber_count += 1;
+        self.fiber_lengths
+            .entry(fiber.record.seq_len() as i64)
+            .and_modify(|e| *e += 1)
+            .or_insert(1);
+        self.ccs_passes
+            .entry(OrderedFloat(fiber.ec))
+            .and_modify(|e| *e += 1)
+            .or_insert(1);
+        if let Some(rq) = fiber.get_rq() {
+            self.rq
+                .entry(OrderedFloat(rq))
+                .and_modify(|e| *e += 1)
+                .or_insert(1);
+        }
+    }
+
+    fn add_m6a_stats(&mut self, fiber: &fiber::FiberseqData) {
+        let m6a_count = fiber.m6a.starts.len() as i64;
+        self.m6a_count
+            .entry(m6a_count)
+            .and_modify(|e| *e += 1)
+            .or_insert(1);
+
+        // now get the ratio
+        let total_at = fiber
+            .record
+            .seq()
+            .as_bytes()
+            .iter()
+            .filter(|&b| *b == b'A' || *b == b'T')
+            .count();
+
+        let ratio = m6a_count as f32 / total_at as f32;
+        self.m6a_ratio
+            .entry(OrderedFloat(ratio))
+            .and_modify(|e| *e += 1)
+            .or_insert(1);
+    }
+
+    fn add_range_lengths(hashmap: &mut HashMap<i64, i64>, range: &crate::utils::bamranges::Ranges) {
+        for r in range.lengths.iter().flatten() {
+            hashmap.entry(*r).and_modify(|e| *e += 1).or_insert(1);
+        }
+    }
+}
+
+impl Default for QcStats {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+pub fn run_qc(opts: &mut QcOpts) -> Result<(), anyhow::Error> {
+    let mut bam = opts.input.bam_reader();
+    let mut stats = QcStats::default();
+
+    for fiber in opts.input.fibers(&mut bam) {
+        stats.add_read_to_stats(&fiber);
+    }
+    Ok(())
+}
diff --git a/tests/basemods.rs b/tests/basemods.rs
index 7b84d3ca..37e34959 100644
--- a/tests/basemods.rs
+++ b/tests/basemods.rs
@@ -1,6 +1,5 @@
 use env_logger::{Builder, Target};
 use fibertools_rs::utils::basemods::*;
-use log;
 use rust_htslib::{bam, bam::Read};
 
 #[test]
@@ -11,7 +10,7 @@ fn test_mods_do_not_change() {
         .target(Target::Stderr)
         .filter(None, log::LevelFilter::Debug)
         .init();
-    let mut bam = bam::Reader::from_path(&"tests/data/all.bam").unwrap();
+    let mut bam = bam::Reader::from_path("tests/data/all.bam").unwrap();
     for rec in bam.records() {
         let mut rec = rec.unwrap();
         let mods = BaseMods::new(&rec, 0);
diff --git a/tests/bio_io.rs b/tests/bio_io.rs
index 01a80d19..ca54ae57 100644
--- a/tests/bio_io.rs
+++ b/tests/bio_io.rs
@@ -1,10 +1,9 @@
 use fibertools_rs::utils::bio_io;
-use log;
 use rust_htslib::{bam, bam::Read};
 
 #[test]
 pub fn test_msp_nuc_tags() {
-    let mut bam = bam::Reader::from_path(&"tests/data/all.bam").unwrap();
+    let mut bam = bam::Reader::from_path("tests/data/all.bam").unwrap();
     for record in bam.records() {
         let record = record.unwrap();
         let _n_s = bio_io::get_u32_tag(&record, b"ns");
diff --git a/tests/extract_test.rs b/tests/extract_test.rs
index 75536e77..9b02b946 100644
--- a/tests/extract_test.rs
+++ b/tests/extract_test.rs
@@ -7,9 +7,8 @@ fn get_fiber_data_from_test_bam(bam_file: &str) -> Vec<fibertools_rs::fiber::Fib
     bam.records()
         .map(|r| {
             let record = r.unwrap();
-            let fiber_data =
-                fibertools_rs::fiber::FiberseqData::new(record, None, &FiberFilters::default());
-            fiber_data
+            
+            fibertools_rs::fiber::FiberseqData::new(record, None, &FiberFilters::default())
         })
         .collect::<Vec<_>>()
 }
@@ -44,8 +43,7 @@ fn test_many_msps() {
             .msp
             .starts
             .iter()
-            .flatten()
-            .map(|&x| x)
+            .flatten().copied()
             .chain(fiber_data.msp.ends.iter().flatten().map(|&x| x - 1))
             .collect::<Vec<_>>();
         eprintln!("m6a: {:?}", m6a);
diff --git a/tests/m6a_prediction_test.rs b/tests/m6a_prediction_test.rs
index 3ceaffd7..25d2f826 100644
--- a/tests/m6a_prediction_test.rs
+++ b/tests/m6a_prediction_test.rs
@@ -1,4 +1,3 @@
-use fibertools_rs;
 use fibertools_rs::utils::bio_io;
 use fibertools_rs::utils::input_bam::FiberFilters;
 use rust_htslib::bam::Reader;
@@ -25,7 +24,7 @@ fn run_prediction_and_count_qual(inbam: String) -> usize {
     let named_tmp_bam_out = NamedTempFile::new().unwrap();
     let out_str = named_tmp_bam_out.path().to_str().unwrap();
     let mut predict_options = fibertools_rs::cli::PredictM6AOptions::default();
-    predict_options.input.bam = inbam.clone();
+    predict_options.input.bam.clone_from(&inbam);
     predict_options.input.global.threads = 1;
     predict_options.out = out_str.to_string();