DENVER – Amid concerns that people are applying for medical marijuana cards just to avoid paying taxes that come when buying retail pot, a committee in the Colorado legislature heard a bill Thursday designed in part to tighten rules on some medical marijuana providers.

HB15-014 requires caregivers to register with the state in order to provide services to patients, among other provisions.

Caregivers are people who grow marijuana on behalf of registered patients, but do not establish a regulated dispensary to sell medical or retail marijuana.

Bill sponsor Sen. Irene Aguilar (D-Denver) presented the bill Thursday saying "what we're really trying to do is provide additional protections" for caregivers. The provisions of the bill, she said, would also allow law enforcement to easily differentiate between legitimate grow operations and illegal cultivation.

Opponents of the bill strongly disagreed with the bill sponsor, arguing that a caregiver registry rounds up the providers and exposes them to risk, particularly if a non-pot friendly president were elected to the White House.

Another MMJ advocate argued that the system is "working fine" as it is now, so he wondered why it needs to change.

Many opponents cited the unconstitutionality of the bill, saying it was taking away rights guaranteed under Amendment 20, which voters passed in November of 2000, legalizing medical marijuana in Colorado.

However, Ben Figa from the Governor's Office of Legal Counsel, testified that after conferring with Colorado Attorney General Cynthia Coffman, the state believes the bill is constitutional. He also echoed Sen Aguilar's remarks, saying the bill would provide additional protections for caregivers.

Several law enforcement groups and agencies supported the bill, saying it would help them uncover illegal growing operations while protecting caregivers with legal grow operations. County commissioners also testified in support of the bill.

Most supporters of the bill shared the same belief that bringing the medical marijuana market "into the light" would help legitimize the industry and benefit the masses.

There was concern about the violation of medical privacy laws as patient records would be shared on some level to ensure that each patient only used one caregiver or one MMJ center. Committee member Sen. Linda Newell said that because marijuana is against federal law, HIPAA, also a federal law, "does not apply here."

The senate public health and human services committee passed the bill unanimously, 5-0. Next it goes to the appropriations committee for funding.