1. Hospital Inpatient Coverage
Endovascular thrombectomy of intracranial arteries for acute ischemic stroke has been and remains a covered procedure for Medicare. However, denials began to occur when ICD-10 went into effect on October 1, 2015.
03CG3ZZ Extirpation of matter from intracranial artery, percutaneous approach
Problem
 The CMS GEM crosswalk tool between ICD-9 and ICD-10 incorrectly equated thrombectomy with angioplasty.
 Code 03CG3ZZ was incorrectly included in NCD 20.7 for percutaneous transluminal angioplasty.
 Code 03CG3ZZ was also incorrectly included in the MCE as a non-covered carotid artery angioplasty procedure.
Now obviously, endovascular thrombectomy of intracranial arteries for acute ischemic stroke has been and remains a covered procedure for Medicare. However, all these cases began to get denied starting on October 1, That’s the date that ICD-10 went into effect. Coincidence? I think not.
The problem centered on how CMS was handling code 03CG3ZZ for the thrombectomy. Basically, when CMS crosswalked ICD-9 code for intracranial angioplasty to ICD-10-PCS, the GEM – the CMS crosswalk tool – said that one of the equivalent codes was 03CG3ZZ. In other words, CMS incorrectly equated thrombectomy with angioplasty for ICD-10-PCS codes. Now, of course, extirpation procedures like thrombectomy and atherectomy have nothing to do with angioplasty. But many, many years ago, extirpation and angioplasty used to be assigned to the same code in ICD-9, and that was apparently the origin of the bad crosswalk. And the bad crosswalk was a real problem. Because while intracranial thrombectomy is a covered procedure for Medicare, intracranial angioplasty is not a covered procedure and never has been, unless it’s being done with stenting in a clinical trial. The upshot was that thrombectomy procedures using 03CG3ZZ were being denied because they didn’t meet criteria for angioplasty and stenting.   
Unfortunately, CMS used the GEM to convert the codes on coverage policies and the codes on the inpatient Medicare Code Editor. So…
- Thrombectomy code 03CG3ZZ was incorrectly included in NCD 20.7 which says that intracranial angioplasty is not covered
and
- Thrombectomy code 03CG3ZZ was also incorrectly included in the Medicare Code Editor as a non-covered carotid artery angioplasty procedure.
Alright, so there were three things that needed to be corrected to fix this problem of inappropriate denials: the GEM, the list of codes in the NCD, and the list of codes in the Medicare Code Editor. >>>>

2. Hospital Inpatient Coverage
Correction
 CMS has issued corrections to the GEM, the NCD, and the MCE.
 GEM corrections were released at the March 2016 meeting of the ICD-10 Coordination and Maintenance Committee.
 Transmittal 1665 (CR9631) issued May 13, 2016 instructed MACs to remove all extirpation codes from NCD 20.7 effective October 1, 2015.
 In the FY 2017 HIPPS rule, CMS finalized a proposal to remove code 03CG3ZZ from the MCE non-covered list, effective October 1.
Medicare Program; Hospital Inpatient Prospective Payment Systems for Acute Care Hospitals … Prospective Payment System and Policy Changes and Fiscal Year 2017 Rates, posted August 2, 2016
 CMS directed MACs to adjust any claims brought to their attention that were denied in error.
Happily, CMS has indeed issued corrections to the GEM, the NCD, and the MCE.
Corrections to the GEM were released at the March 2016 meeting of the ICD-10 Coordination and Maintenance Committee, which is chaired by CMS. If you’re interested in seeing this for yourself, the link is right there on the slide under the check mark.
Then in May 2016, CMS released Transmittal 1665 (CR 9631) instructing MACs to remove all the extirpation codes from NCD 20.7, effective October 1, Again, the link is provided. I might note that was a subsequent update to Transmittal 1665 on June 3, 2016 (Transmittal 1672, CR 9631) but it didn’t impact this part.
Now, correcting the Medicare Code Editor has been trickier. MCE changes are legally required to go through the formal rule-making process, which is why CMS couldn’t just pull the bad code. So in the proposed hospital inpatient rule for FY 2017, they formally proposed removing code 03CG3ZZ from the MCE list of non-covered procedures. This was finalized in the final rule posted to the CMS website on August 2, and goes into effect on October 1, 2016, the first day of FY 2017.
In the meantime, CMS also directed the MACs to adjust any claims brought to their attention that were denied in error.
Links are provided for all of these bullets, and there’s a nice summary of the situation at the last link at the bottom of the slide where it says “see also”.
So what to do going forward. >>>>
see also:

3. Hospital Inpatient Coverage
Going Forward
 MACs should now be paying these claims routinely. However, they have no instructions to automatically reprocess previously denied claims.
 Hospitals should contact their specific MAC and work with them on getting denied claims paid.
 If problems continue, hospitals can contact the Coverage and Analysis Group at CMS with specific remittance advice examples of denied claims.
 Alternately, hospitals may be able to contact manufacturers with specific examples (de-identified) and ask them to serve as intermediaries in obtaining payment.
MACs should now be paying these claims routinely now. But … you may have noticed that they received no instructions to automatically reprocess previously denied claims. You have to ask, claim by claim.
Hospitals should contact their MAC directly with a list of any and all claims that were inappropriately denied and then, as CMS puts it, “work with” the MAC on getting them turned around and paid. You may not need to go through a formal appeal.
If problems do continue, hospitals can contact the Coverage and Analysis Group directly at CMS. They’ll need to see specific remittance advice examples of denied claims that are not being fixed by the MAC.
Or hospitals may be able to contact manufacturers with specific examples (de-identified) and ask them to serve as intermediaries, many manufacturers will run this kind of interference as a customer service.
Okay, I hope this has been helpful to you in understanding the clinical aspects of acute ischemic stroke and stent retriever thrombectomy, the ICD-10 codes for the diagnoses and procedures, the typical DRGs assigned, and why your payments were being held up and what to do about it!