# CPAP Titration and Split-Night Sleep Studies

A CPAP titration study finds the air pressure that keeps your airway open; a split-night study combines diagnosis and titration in one night when sleep apnea is clear early on.

Updated 2026-10-28. Also on the [web page](https://sleepstudies.fyi/guides/cpap-titration-and-split-night-sleep-studies).

Once sleep apnea is diagnosed, the next question is **how much pressure** you need. That's what titration answers.

## Full-night titration

During a CPAP titration (CPT 95811), you sleep in the lab wearing a mask. The technologist raises the pressure step by step, watching for apneas, hypopneas, snoring and arousals, until breathing is stable in all sleep stages, ideally including REM sleep on your back. The result is a prescribed pressure, or a pressure range for auto-CPAP.

Titration is also used for **BiPAP** and **ASV** in people with central sleep apnea, high pressure needs or lung disease.

## Split-night study

A split-night study puts diagnosis and treatment in one night:

1. The first part is a standard diagnostic study.
2. If moderate-to-severe obstructive sleep apnea is clear early on, typically within the first two hours, the technologist wakes you and fits a mask.
3. The rest of the night, usually at least three hours, is spent titrating pressure.

### Pros
- One night instead of two
- Lower total cost
- Faster start on therapy

### Cons
- Less titration time, which may miss REM-related events
- Mild apnea may not meet the threshold to switch

## Tips for a successful titration

- Ask to try the mask briefly before lights out.
- Tell the technologist if you breathe through your mouth.
- Mention claustrophobia; nasal pillows can help.
- Bring your own mask if you already have one.

After titration, your prescription goes to a DME supplier. The 90-day clock for insurance compliance starts when you receive the machine.

## Questions

### Do I need a titration study if I have an auto-CPAP?

Not always. Many adults with uncomplicated obstructive sleep apnea start on auto-adjusting CPAP at home. In-lab titration is still preferred for complex cases, central apnea or when auto-CPAP doesn't work.

### What if I can't tolerate the mask during the split night?

The technologist will try other masks and settings. If titration can't be completed, your physician may order a separate full titration night.

### Is a split-night study billed differently?

Yes. A split-night or titration study is usually billed as CPT 95811 rather than the diagnostic code 95810.